07-20-2014, 01:23 PM
My approach is similar to Kestas. I tend to use schematics from Nostalgia Air, but some from alternate sites. This site has some great links for schematics and other reference material. I find the tube of interest in some tube manuals I have downloaded for reference. Then I use Adobe Photoshop software to enter the pin numbers on the schematic I have available then print the schematic out for use as I work on the radio. Some data such as capacitors and resistors and even voltages on schematics are such poor image quality that one has to compare what is on the schematic against what the parts list (if available) shows. In those cases I erase the existing blurry text on the schematic and enter new text showing the values from the parts list.
One has to also understand that during the 1920s and 1930s many abbreviations, designators and schematics did not use the modern schematic standards we are so used to today. Often the designation 50M ohm may mean 50,000 ohms using the old Roman Numeral letter M to represent thousands.
Many early tube illustrations show grids with the same symbol used for resistors. The dashed line illustration of grids inside tubes came along later. Standards changed slowly over time.
Help is always available here if you get stumped.
Joe
KC5LY
One has to also understand that during the 1920s and 1930s many abbreviations, designators and schematics did not use the modern schematic standards we are so used to today. Often the designation 50M ohm may mean 50,000 ohms using the old Roman Numeral letter M to represent thousands.
Many early tube illustrations show grids with the same symbol used for resistors. The dashed line illustration of grids inside tubes came along later. Standards changed slowly over time.
Help is always available here if you get stumped.
Joe
KC5LY
